If you eat a cup of blueberries every day, your chance of developing cardiovascular disease will decrease by 15 percent. Researchers from the University of East Anglia in the UK report this in the American Journal of Clinical Nutrition.

Study
The researchers experimented for half a year with a group of 115 overweight or obese test subjects aged 50-75. All test subjects, such as thirty percent of all residents of somewhat developed countries, had metabolic syndrome. The metabolic syndrome is a complex of, among other things, insulin resistance, a deterioration in cholesterol levels and a decrease in the health of the vessel walls.

The researchers divided the subjects into 3 groups. For six months, a control group received a placebo, and two experimental groups received a dish each day with 75 or 150 grams of blueberries, respectively. It has never happened before that in a clinical study so many people have been given blueberries for so long.

Sponsor
This study was sponsored by the US Highbush Blueberry Council, [ushbc.org] an organization for blueberry growers.

Results
Eating a dish containing 150 grams of blueberry every day for six months resulted in an increase in the flexibility of the blood vessels [FMD].

In the placebo group, the concentration of the second messenger cGMP in the blood vessels decreased; in the experimental groups, this concentration remained at the same level. Less cGMP means stiffer blood vessel walls, more cGMP means more flexible blood vessel walls. An erection agent such as sildenafil works by reducing the breakdown of cGMP in the corpus cavernosum.

Blueberries had no effect on the cholesterol balance of the test subjects as a whole. But when the researchers nodded the statin users out of their samples, it suddenly turned out that blueberries slightly increased the concentration of 'good cholesterol' HDL.

The researchers actually expected that an intake of 75 grams of blueberries per day would also improve the cardiovascular health of their test subjects. But in that group the concentration of the bioactive substances in blueberries did not increase significantly. You see that above.

Conclusion
"Having metabolic syndrome significantly increases the risk of heart disease, stroke and diabetes and often statins and other medications are prescribed to help control this risk", tells research leader Aedin Cassidy in a press release. [sciencedaily.com May 30, 2019] "It's widely recognised that lifestyle changes, including making simple changes to food choices, can also help."

"Previous studies have indicated that people who regularly eat blueberries have a reduced risk of developing conditions including type 2 diabetes and cardiovascular disease. This may be because blueberries are high in naturally occurring compounds called anthocyanins, which are the flavonoids responsible for the red and blue colour in fruits."

"We found that eating one cup of blueberries per day resulted in sustained improvements in vascular function and arterial stiffness, making enough of a difference to reduce the risk of cardiovascular disease by between 12 and 15 per cent", says first author Peter Curtis. "The simple and attainable message is to consume one cup of blueberries daily to improve cardiovascular health."

"Unexpectedly, we found no benefit of a smaller 75 gram (half cup) daily intake of blueberries in this at-risk group. It is possible that higher daily intakes may be needed for heart health benefits in obese, at-risk populations, compared with the general population."